A leakage current of a schottky barrier diode (hereinafter referred to as “SBD”) when an opposite direction voltage is applied is larger than that of a PN diode, since in an interface between a schottky electrode and a semiconductor, the difference of work function between the electrode material, i.e., metal, and the semiconductor is small.
In order to decrease the leakage current, a constitution that a PN diode is formed in a part of a schottky junction and a leakage current when an opposite direction voltage is applied is suppressed is proposed, which is disclosed in JP-A-2000-252478. Specifically, a frame-shaped p-type resurf layer is arranged at a peripheral portion, which surrounds a region in which a schottky electrode and an n-type semiconductor layer are made to be a schottky contact, and high impurity concentration p-type semiconductor layer is arranged in a stripe manner or is sprinkled inside the resurf layer so that the p-type semiconductor layer is in contact with the schottky electrode.
In the junction barrier schottky diode (hereinafter referred to as “JBS”) as shown in the above reference, the p-type semiconductor layer is formed based on a simulation for a pressure-proof design and width and distance of each of the p-type layers are controlled appropriately so that the pressure-proof JBS can be obtained. Therefore, it is difficult to obtain both the pressure-proof JBS and a low resistivity p-type layer, and the JBS of the above reference lacks versatility.